502 Queries and Ansxoers. 



apparatus, and at little expense. For instance, the law of chemical attrac- 

 tion, and the chemical and mechanical properties of the gases, &c., may be 

 proved at a very small cost. Oxyj^en may be procured sufficiently pure, by 

 placing a bell-glass in water, and introducing some leaves; then exposing 

 them to sunshine, and removing them as soon as faded, or before night. 

 This procured, its properties can be examined. Sulphur, phosphorus, &c., 

 may be burned in it, and acids formed, &c. Hydrogen gas may be procured 

 by putting diluted sulphuric acid upon zinc or iron filings into a Florence 

 flask, furnished with a bent tin tube. During the action caused by the dis- 

 engagement of the gas, an example of single elective affinity may be 

 observed. Its great lightness, and, by mixing it with about a third of 

 atmospheric air, its explosive properties, may be ascertained, &c. The 

 residue may be filtered, evaporated, and crystallised ; and may be used with 

 nut galls in making ink, and in numerous other experiments. Carbonic 

 acid gas may be easily obtained from lime, chalk, shells offish, &c., by the 

 addition of any of the more potent acids : its properties may be also exa- 

 mined. In fact, where there is a willing mind, combined with perseverance, 

 more may be done than we might anticipate. 



Mr. Taylor farther asks, " What is the simplest test for detecting the 

 oxide of iron in soils and subsoils ? " In answer, I would state, that, for 

 any of the salts of iron, an infusion of nut galls, of tea, or of any other 

 vegetable containing a quantity of astringent matter, will detect it. These 

 form a black precipitate with all the salts of iron; but, if the iron or 

 astringent matter is in minute quantities, a black colour will only be given 

 to the solution. This black precipitate is a compound of the astringent 

 principle of the vegetable and the oxide of iron. Prussiate of potass forms 

 a beautiful blue precipitate with some of the salts of iron. I would here 

 caution your querist from making any inferences from empirical analyses; as 

 bodies composed of the same elemental parts, but joining in different de- 

 finite proportions, form very different substances, and, of course, possess 

 very distinct properties. As analysis is the most intricate part of practical 

 chemistry, and requires a degree of discrimination and nice manipulation, 

 combined with a thorough knowledge of the science, which cannot be 

 expected from a working gardener, it would, perhaps, be better, before any 

 deductions are made, to have the soil analysed by a neighbouring chemist, 

 as you have, I think, somewhere recommended. I am. Sir, yours, &c. — 

 Ej)hebicus Horticultor. Peeblesshire, Feb. 21. 1833. 



WhitelnU, the seat of Isaac Cookson, Esq., near Durham, we are in- 

 formed, is one of the neatest kept places in England, and one where the 

 journeymen are remarkably well treated. Will the gardener there, or any 

 of our readers, give us a description of the place, and of the mode of 

 garden management ? — Cond. 



Wild Plants declare the Qualify of the Soils in which they flourish. — A 

 knowledge of the habitat of plants is of so much importance, that I am sur- 

 prised the hint given under the head " Soil," in Dr. Willich's Domestic 

 Encyclopcedia, has not been adopted. He says, " if an accurate geogra- 

 phical catalogue of such vegetables as grow in particular situations were 

 published in every country, it would be of great service in ascertaining 

 the degree of fertility, as well as the nature, of the different soils. — 

 C. M. W. March 12. 1833. 



Plane Trees, (p. 379.) — In relation, I must not say in answer, to Mr. 

 Rutger's question in p. 379. on plane trees, I may state that trees of the 

 western plane (Platanus occidentalis L.) are not rare close around London, 

 and some grow actually in it, as in Piccadilly, in some of the squares, &c. : 

 those I have seen both around and in London seem thriving and well- 

 conditioned. I once had to plant, and did plant, some fine young western 

 plane trees into a heavy, even partially clayey, loam, in a low meadow 

 through which watercourses ran, and still run ; and where the soil, from 



